1. Field of the Invention
The present invention is related to vitreous cutters and sleeves that are used in vitrectomy procedures to remove vitreous from the eye. In particular, the present invention is related to vitreous cutters and sleeves having a light source to illuminate a portion of the eye.
2. Background and Description of Related Art
Vitrectomy is a procedure in which the degenerative vitreous is removed to clear the opaque optical media (vitreous) or to eliminate traction on the retina which produces a localized or generalized retinal detachment. The function of a vitrectomy instrument is described in U.S. Pat. No. 4,099,529 to Peyman, the entire contents of which are herein incorporated by reference. That is, generally, the cutting part includes concentric tubing. An inner tube serves as the inner cutting edge of the instrument and has an oscillating action, and the opening in the tightly fit outer tube serves as the outer edge of the cutting. The vitreous is aspirated through a small opening close to the tip of the outer stationary tube, i.e., the outer cutting edge. The aspiration force, generated by a pump, when applied through the inner tube draws the vitreous through the outer hole toward the inside of the inner tube. The oscillation of the inner tube cuts the vitreous/tissue trapped in the opening of the outer tube and is aspirated into a reservoir. To balance the intraocular pressure, physiologic saline solution is infused through a second independent “infusion tube” placed inside the eye cavity through a separate incision in the eye wall.
During the procedure, the vitreous cavity is illuminated through a separate fiber optic brought inside the eye through a third incision. The diameter of the vitrectomy cutting cutters varies between 20-23-25-27 gauge. The most desirous sizes are 23 gauge, 25 gauge, and 27 gauge tubes because these sizes eliminate the need to close the incision in the eye wall by a suture and the smaller the instrument is, the less traumatic the surgery becomes.
There are several disadvantages of the conventional systems. First, there is a need for at least three incisions for the cutter, infusion and the light sources. Second, the 25 gauge and 27 gauge tips, because of their size are too flexible inside the eye. That is, the slightest pressure that moves the eye during surgery also can bend the shaft of the cutter in one direction at the incision site while the inside portion of the shaft moves in another direction. This movement can be disturbing to an operator who does not expect motion in the opposite direction than that which was intended and can cause injury to the fine structure of the lens or the retina. Third, in myopic eyes having a longer axial length than normal, a longer (36-38 mm) than normal shaft (e.g., 30 mm) is required. This makes the instrument flimsy and not desirable.
In addition, in conventional systems, the tip of the vitrectomy instrument, which often contacts a contaminated portion of the eye, such as a tumor, may spread contaminated and cancerous tissue to other healthy portions of the eye. As such, what is needed is a device for containing the contaminated tip of the vitrectomy instrument after it is used to penetrate contaminated tissue of the eye so that any residual contaminated tissue present on the tip of the vitrectomy cutter is not spread to other, healthy portions of the eye as the vitrectomy instrument is being removed from the eye at the conclusion of the procedure. In addition, there is a need for the device, which contains the contaminated tip of the vitrectomy instrument, to incorporate other integral features that facilitate the performance of the procedure on eye.